Kimi Raikkonen is rejoining Ferrari with whom he won the world championship in 2007. Photograph: Gero Breloer/EPA

The Finnish Formula One driver Kimi Raikkonen said he left Lotus and re-signed for Ferrari due to a dispute over money.

"The reason why I left the team is really on the money side. The team said they haven't got my salary. It's an unfortunate thing," Raikkonen said.

Asked why he was continuing to drive for Lotus if he was not being paid – the issue is understood to centre around performance-related payments rather than his basic wage – Raikkonen said: "I like to race.

"That's the only reason why I'm here, it doesn't matter which team it is."

Raikkonen has indicated he might have stayed with Lotus if they had resolved their financial issues.

The 33-year-old Finn said: "They know what it is. Hard to say which way it would have gone if it had happened, but the deal is done and I'm happy."

Raikkonen last week opted to sign a two-year deal with the team that made him world champion in 2007.

In replacing Felipe Massa, Raikkonen is to partner Fernando Alonso from 2014, forming a partnership the seven-times champion Michael Schumacher has already suggested could be "explosive".

"I don't see any reason why it wouldn't work," said Raikkonen. "We are all old enough to know what we are doing, and the team is working for the right kind of things to make sure.

"If there is something then I'm sure we can talk it through. It's not like we are 20-year-old guys any more.

"I might be wrong, time will tell, but I'm pretty sure it will be good. Of course, there will be hard fights on the circuit, and sometimes things go wrong, but I'm pretty sure it will be OK."

Despite seemingly leaving Ferrari under a cloud at the end of 2009, with the final year of his contract paid off as the team brought in Alonso, Raikkonen feels all that went before is now water under the bridge.

"I always had freedom there – just a lot of stories from my past from different teams," said Raikkonen.

"I had a good time and I'm sure we'll all have a good time together again. I never had a bad feeling with them.

"I've still a lot of friends and good memories from my time there. I know the team and the people, some have left since I was last there, but I don't think it will be too different to go there and do well again."